To enable applications such as mpg321 to use the Hifi-Shield even when no pulseaudio daemon is running (e.g. from a cron job),
add one more line to the end of the file /etc/pulse/default.pa :

suspend-sink alsa_output.platform-odroid_sound_card.5.analog-stereo 1

Note: Applications like mpg321 will start a pulseaudio daemon if there isn't one running already. However, the Hifi-Shield cannot be opened until the pulseaudio suspend-on-idle timeout expires. This causes the application to exit with an error message reporting that the Hifi-Shield is busy.

To test, connect an amplifier to the 3.5mm or RCA lineout jack on the Hifi-Shield, reboot the C1+, and then run:

aplay/usr/share/sounds/alsa/Front_Center.wav

Credit:
This instruction was made by culler (our forum member). Original Post

Update
If your kernel version is 3.10.96-143 or higher, the I2S/DAC drivers have been changed to modules.
So you need to load the modules before enable the Hifi-Shield.
Refer this LINK